#ifdef WIN32
#include <windows.h>
#endif

// Engine headers
#include "common.h"
#include "system.h"

using namespace Led::System;
using namespace Led::Math;

/// Constructor.
PhysicsHandler::PhysicsHandler()
{
	sim = NULL;
}

/// Initialize. Initializes the physics manager and preserves space for the amount of bodies.
/// @variable int rigbodies the amount of rigid bodies.
/// @variable int animbodies the amount of animated bodies.
int PhysicsHandler::Initialize(int rigbodies, int animbodies)
{
	unsigned long totalbodies = 0;
	neSimulatorSizeInfo sizeinfo;

	// Setup our physics engine info.
	sizeinfo.rigidBodiesCount = rigbodies;
	sizeinfo.animatedBodiesCount = animbodies;

	// Calculate the total amount of bodies.
	totalbodies = sizeinfo.rigidBodiesCount + sizeinfo.animatedBodiesCount;
	sizeinfo.geometriesCount = totalbodies;

	// Calculate the max pair of overlapping bodies.
	sizeinfo.overlappedPairsCount = totalbodies * (totalbodies - 1) / 2;
	sizeinfo.rigidParticleCount = 0; 
	sizeinfo.constraintsCount = 0; 
	sizeinfo.terrainNodesStartCount = 0;

	// Set our gravity.
	gravity.Set(0.0f, -10.0f, 0.0f);

	// Finally create our simulator.
	sim = neSimulator::CreateSimulator(sizeinfo, NULL, &gravity);

	return 0;
}

/// Run. Runs the physics every frame.
int PhysicsHandler::Run()
{
	if (sim != NULL)
		sim->Advance(1, 2, NULL);

	return 0;
}

/// Destroy. Destroys the physics manager.
int PhysicsHandler::Destroy()
{
	// Destroy the simulator.
	neSimulator::DestroySimulator(sim);

	// Set sim to NULL.
	sim = NULL;
	
	return 0;
}

/// SetTerrainMesh. Sets the terrainmesh pointer.
/// @variable neTriangleMesh mesh the new mesh.
int PhysicsHandler::SetTerrainMesh(neTriangleMesh *mesh)
{
	if (sim)
		if (mesh != NULL)
			sim->SetTerrainMesh(mesh);

	return 0;
}

/// GetSimulator. Returns a pointer to the simulator.
neSimulator *PhysicsHandler::GetSimulator()
{
	return sim;
}

#ifndef PHYSICSHANDLER_H
#define PHYSICSHANDLER_H

namespace Led
{

	namespace System
	{
		class PhysicsHandler
		{
		public:
			/// Constructor.
			PhysicsHandler();

			/// Initialize. Initializes the physics handler and preserves space for the amount of bodies.
			/// @variable int rigbodies the amount of rigid bodies.
			/// @variable int animbodies the amount of animated bodies.
			int Initialize(int rigbodies, int animbodies);

			/// Run. Updates the physics every frame at the given speed.
			int Run();

			/// Destroy. Destroys the physics handler.
			int Destroy();

			/// SetTerrainMesh. Sets the terrainmesh pointer.
			/// @variable neTriangleMesh mesh the new mesh.
			int SetTerrainMesh(neTriangleMesh *mesh);

			/// GetSimulator. Returns a pointer to the simulator.
			neSimulator *GetSimulator();

		private:
			neV3 gravity;
			neSimulator *sim;
		};
	};
};

#endif

/// GeneratePhysicsModel. Generates the model's physics information.int HeightObject::GeneratePhysicsModel(){	// Now we're done with that, let's generate some information for the physics engine.	terrainbody.vertexCount = num_verts;	// Create a new vertice array specially for the physics manager.	terrainverts = new neV3[num_verts];	for (int i = 0; i < num_verts; i++)	{		terrainverts.Set(vertbuffer.x, vertbuffer.y, vertbuffer.z);	}	// Assign the terrain's vertices.	terrainbody.vertices = terrainverts;	// Calculate the amount of triangles in the terrain.	terrainbody.triangleCount = ((width-1)*(height-1)*2);	terraintris = new neTriangle[terrainbody.triangleCount];	int dindex = 0;	// Generate a triangle array.	for (int x = 0; x < width - 1; x++)	{		for (int y = 0; y < height - 1; y++)		{			terraintris[dindex].indices[0] = x + y * width;			terraintris[dindex].indices[1] = x + (y + 1) * width;			terraintris[dindex].indices[2] = (x + 1) + y * width;			terraintris[dindex].materialID = 0;			terraintris[dindex].flag = neTriangle::NE_TRI_TRIANGLE;						dindex += 1;			terraintris[dindex].indices[0] = x + (y + 1) * width;			terraintris[dindex].indices[1] = (x + 1) + (y + 1) * width;			terraintris[dindex].indices[2] = (x + 1) + y * width;			terraintris[dindex].materialID = 0;			terraintris[dindex].flag = neTriangle::NE_TRI_TRIANGLE;						dindex += 1;		}	}	// Set the terrain's triangle pointer.	terrainbody.triangles = terraintris;	//engine->GetPhysicsHandler()->GetSimulator()->SetTerrainMesh(&terrainbody);	return 0;}